It’s almost impossible to judge within a reasonable degree of accuracy, and even then there is a lot of subjective bias. It would require putting in the same amount of preparation work, and for general knowledge of the material to be the same at the time of writing both exams to even have a chance at evaluating the difficultly between the two.
I felt this year’s exam was easier, but I was way more prepared, so there you go. The most likely answer is that the relative difficulty year over year is roughly the same.